The present invention relates generally to the field of computer-based information retrieval, and more specifically to the application of natural language processing (NLP) techniques to the interpretation and representation of computer text files, and to the matching of natural language queries to documents with the aid of user interactions.
Computer-based information retrieval is now an established industry serving many professional communities. Retrieval technologies used in this industry share many common features. For example, a user of these systems is typically required to either (1) state an information need, or query, in a circumscribed manner, usually by demarcing the logical requirements of the query as a sequence of terms linked by various operators, or (2) write the query as free-form text, which is then parsed automatically into a sequence of words or phrases, without regard for the logical form of the query or the underlying meaning of the query. In either event the query is represented only by the collection of words that are overtly stated in the query text (or limited stemmed forms of some words, such as plurals). The matching of documents to a query is based on the co-occurrence of these words or phrases.
A second commonality among retrieval systems is that a query representation derived from a user's query statement is automatically formed by the computer system, with limited or no interaction with the user. In most retrieval systems, once an initial query statement has been made in full, the computer system interprets the contents of the query without allowing the user to verify, clarify or expand upon query representations created by the computerized retrieval system. In the same fashion, the subsequent display of retrieved documents is largely under computer control, with little user interaction.
In view of these common characteristics of computer-based retrieval systems, their inability to capture both the preciseness and richness of meaning in queries and documents, and their inability to interact with the user to help formulate a query statement and present retrieved documents, retrieval is often an inexact process.